Topical mitomycin C therapy for carcinoma in situ of the bladder: a followup.

We studied 15 patients with histologically proved multifocal carcinoma in situ of the bladder who were in remission at a mean followup of 21 months after induction intravesical chemotherapy with mitomycin C. These patients have been followed for a further 28 months, for a total mean duration of 49 months. Of the 15 patients 4 suffered new areas of carcinoma in situ, including 3 who subsequently required cystectomy (2 after unsuccessful intravesical bacillus Calmette-Guerin therapy and 1 with a simultaneous invasive tumor). One patient underwent transurethral resection of the prostate for carcinoma in situ of the prostatic urethra, which subsequently was shown to be limited to mucosa and not involving the deeper ducts nor the stroma. Of the remaining 11 patients 1 died of unrelated disease and 2 suffered recurrent papillary transitional cell carcinoma treated successfully with a combination of intravesical bacillus Calmette-Guerin therapy and resection. The other 8 patients have remained free of tumor. None of the 15 patients had metastatic cancer. We believe that these results support the durability of response after induction mitomycin C therapy. We stress the necessity for prolonged close followup to detect recurrent tumor and to avoid metastatic disease.